Positioning and repositioning systems for fixing toolholders to the drums of milling machines

ABSTRACT

Improvements to the positioning and repositioning systems for the fixing of toolholders ( 3 ) to the drums of milling machines. The cylindrical shell of the drum ( 1 ) presents through slots ( 2 ) which allow a reliable positioning of the toolholders ( 3 ) during the removal operations. The toolholders ( 3 ) present congruent reference element ( 4, 4′, 4 ″) that engage the through slots ( 2 ).

[0001] The present invention concerns the technology of milling machines drums, especially systems to perform the positioning and assure repositioning for the fixing of toolholders placed around the cylindrical surface of the drums of milling machines. International classification B21d, E21c.

STATE OF THE ART

[0002] It is known that the drums in milling machines are provided with a number of toolholders specifically located and oriented in different positions at different angles. The right positioning of each toolholder requires the employment of complex gears for the industrial production of milling machines' drums.

[0003] It is also known that both tools and toolholders are worn out during the milling activity and the problem of replacing them often occurs. During the removal activity of the toolholder with oxyhydrogen flame often happens that even the references for repositioning of the spare toolholder are effaced. In cases of serious wear even the references consisting in prominent bases are erased, and also the references made by a flat surface on the drum in the position where the toolholder need to be fixed.

[0004] The problem to be solved is to preserve the specific repositioning references to always guarantee the right positioning of spare toolholders.

[0005] It should be pointed out that the replacement operations of the toolholders are done manually, without sophisticated industrial production tools.

[0006] The present invention suggests an improved system to solve the above mentioned problems, and guarantees the possibility to replace correctly the spare toolholders even in cases of serious wear around the fixing zone on the drum that causes the disappearance of references necessary to the positioning of spare toolholders.

DESCRIPTION

[0007] The invention is now disclosed with reference to the figures if the attached drawings as not limiting example.

[0008]FIG. 1 shows in perspective a milling machine industrial drum provided with a plurality of toolholders especially placed and welded upon the cylindrical surface of the drum. It can be noticed that the toolholders have a specific angle that is obtained through the employment of complex equipment for the automatic placement operated by numeric control machines.

[0009]FIG. 2 shows a toolholder provided with specific element of reference.

[0010]FIG. 3 indicates an axial section of the drum shell, upon which are special through slots geometrically congruent with the correspondent reference elements that each toolholders has.

[0011]FIG. 4 shows a transversal section of the drum by a toolholder, which is already in place but not yet welded. It can be noticed the inserting of the reference element in the corresponding slot on the cylindrical shell of the drum.

[0012]FIG. 5 highlights the welding to fix the toolholder, whose positioning is guaranteed by the reference element inserted in the congruent slot on the drum.

[0013]FIG. 6 represents a toolholder with two cylindrical reference elements.

[0014]FIG. 7 represents a toolholder with three cylindrical reference elements.

[0015]FIG. 8 represents a toolholder with a shaped reference element.

[0016]FIG. 9 shows a drum equipped with toolholders with their own milling tool.

[0017] In the figures each detail is marked as follows:

[0018]1 indicates the hollow cylindrical drum of a milling machine

[0019]2 are the through slots that go through the drum shell.

[0020]3 indicates a toll-holder

[0021]4, 4′ and 4″ indicate the reference elements with which the toolholders are provided.

[0022] It should be highlighted that said reference elements are geometrically congruent with the correspondent slots in which they are inserted to guarantee the right position of the toolholder on the drum.

[0023]5 indicates the milling tool fixed onto the toolholder.

[0024] The clearness of the figures highlights the simplicity and total reliability of the improved system which is the object of the present invention.

[0025] It is evident that the slots that go through the hollow shell of the drum will be always present even in extreme situations in which each reference point could disappear, thus not being properly located.

[0026] The slots that go through the cylindrical mantel of the drum constitute the inventive core of the present improved system. These ineffaceable slots allow always for the exact repositioning of the spare toolholder, that could be welded upon the drum with its own original geometric set-up.

[0027] The invention of course allows several versions of practical realization, as far as the structural proportioning, the morphologic and technological choices of the reference elements and their congruent slots are concerned. 

1) Improvements to the positioning and repositioning systems for the fixing of toolholders to the drums of milling machines, characterized by the fact that the cylindrical shell of the drum (1) presents through slots that remain free, ineffaceable and always easy to locate even in case of total wear and disappearance of prominent bases or of flat zones arranged on the drum for placing toolholders (3). 2) Improvements to the positioning and repositioning systems for the fixing of toolholders to the drums of milling machines, as in claim 1, characterized by the fact that the through slots (2), specially placed around the cylindrical surface of the drum (1), are pre-oriented that is geometrically arranged to guarantee the optimal lay-out for each toolholder (3), which is provided with congruent reference element (4, 4′, 4″) that engage in such through slots (2) before it is welded onto it oriented and distributed position around the cylindrical surface of the drum (1). 3) Improvements to the positioning and repositioning systems for the fixing of toolholders to the drums of milling machines, as in previous claims, characterized by the fact that the reference elements (4, 4′, 4″) for the placements of toolholders (3) can be realized in thermolabile material, which melt, during the removal operation with oxyhydrogen flame of the worn out residual toolholders to be replaced, thus freeing the through slots (2) that are always present onto the cylindrical shell of the drum (1). 